The Paragon Double Barrel is just the right size for heat treating and case hardening gun parts and knives. Experiment with color base hardening. Restore the faded colors of historic guns. As with the other Paragon furnaces, the Double Barrel has a digital controller so you can program the exact temperature and hold time that you need. The controller eliminates guesswork. Instead of estimating a temperature by the color of the heat, just enter a temperature into the controller. You will no longer have to adjust a switch to maintain the hold time for case hardening; the controller maintains the hold time for you. Set the hold time for as long as necessary (typically two hours). You can also order a Paragon Double Barrel heat treating furnace with either a drop door or a side-swing door. (The photo above shows the traditional drop door.) The drop door is hinged at the bottom; the side-swing door is hinged at the side. The price of the furnace is the same with either door style. Both doors also include the door safety switch. The door micro safety switch shuts off the power to the elements when the door is opened, yet the temperature controller remains powered. The safety switch is standard on the Paragon Double Barrel furnace.